For a hydraulic supply within a lift frame, it is required to arrange one or more hydraulic lines within the lift frame and to position them advantageously for operation of the lift frame.
A lift frame for an industrial truck, in which hydraulic hoses are arranged for auxiliary hydraulics, is known from U.S. Pat. No. 7,255,201 B2. The known lift frame includes a stationary mast and at least one lift mast displaceable relative thereto. The lift mast has a lift carriage that can be moved up and down, in which auxiliary hydraulics are provided. A hydraulic hose, which is displaced along the lift frame, ends at the lift carriage, wherein a loop open toward the top is formed in a lower end of the lift frame. The hydraulic hose is guided with its loop around a tensioning pulley which is fastened on a pulley carrier. The pulley carrier is arranged in a height-adjustable manner on the lift frame in order to build up pretension for the hydraulic hose during lifting of the lift carriage together with the upper end of the hydraulic hose. For this, the pulley carrier, which maintains the pretension due to its tare weight or additional weights, is mounted in a height-adjustable manner on the lift frame.
Besides the known solution of holding a hydraulic hose, the one end of which moves in height, under pretension also during the height adjustment, the problem also exists of holding a hydraulic hose, which is arranged tightly against the lift frame along the lift frame, under constant pretension. As is known, hydraulic hoses are preferably made of plastic or rubber and plastic composites so that an elongation of the hose, so-called creeping, can occur because of material fatigue in the case of a hydraulic hose under constant pretension. The hydraulic hose hereby loses some pretension and its exact position within the lift frame can be lost. In the case of the known solutions for an arrangement of the hydraulic hose under pretension, an imprecise positioning and play occurs in the hose guide through the elongation of the hose.